Familial medullary thyroid carcinoma: report of three cases in a family

Familial medullary thyroid carcinoma is a distinct clinical entity in which early diagnosis by screening of family members for elevated calcitonin levels can be useful. A 33-year-old female was hospitalized because of an enlarging left thyroid mass. Resected thyroid showed medullary thyroid carcinoma. Her mother had received a total thyroidectomy due to the same disease 10 years previously, and her younger brother had an elevated basal calcitonin level of 468 pg/mL when the index case was diagnosed. The younger brother was advised to undergo surgery; a total thyroidectomy also revealed medullary thyroid carcinoma. There was no evidence of multiple endocrine neoplasia in the family. Recognition of new cases by screening with a basal or provocative test in families of patients with medullary thyroid carcinoma should be mandatory.